Healthier Diet May Up Gut Bacteria, Help Health

We each are living with millions of bacteria teeming in our gut that help us metabolize food and stay healthy.

Now a new study suggests that shifting to a fiber-filled healthy diet with fruits and vegetables may increase the bacteria species in our gut and that in turn, may improve metabolic abnormalities linked to obesity.

Published in Nature yesterday, the study works in tandem with another in the same issue that suggests having a diverse array of bacteria makes a difference to our health. People with less bacteria diversity had more insulin resistance and inflammation, which are risk factors for cancer. They also were also more likely to gain weight.

In the diet study, researchers looked at the microbial diversity among 45 people who were overweight or obese. The scientists analyzed the number of bacteria genes, dividing the group into those who had low or high bacterial diversity: 40 percent had low; 60 percent high. To start with, the people with less bacterial diversity had higher insulin resistance, triglycerides, and inflammation.

The participants then went on a 6-week diet: they cut calories, ate more fruits, vegetables, and fiber, and ate less sugar and fat. The diet was followed by a 6-week maintenance period, where they ate healthier than at the start but fewer fruits and vegetables than during the diet.

At the six-week mark, bacterial diversity had increased among those who started out with low bacterial diversity. These people also had smaller hips, less body fat, improvements in cholesterol and a trend towards lower inflammation. This suggests that eating a fiber-filled healthy diet may lead to permanent changes in gut bacteria, the authors conclude, but more research is needed.

The studies were relatively small but if verified the findings could play a role in cancer prevention, as well as other chronic diseases. Obesity increases the risk for seven cancers, including colorectal cancer. And it could help explain why eating a fiber-rich diet reduces the risk of colorectal cancer, a finding from AICR’s report and its continuous updates.